The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials, design, and fabrication tools have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of these advances, fabrication methods and materials have been developed to realize the desire for smaller feature sizes.
Photoresists are photosensitive materials used to transfer images to a substrate. A coating layer of photoresist is positioned on the substrate and then exposed (or irradiated) through a photomask Proper photoresist processing is critical to development of smaller feature sizes. However, reflection of the radiation used to expose a photoresist can limit the resolution ability of a process. For example, reflection of radiation from a substrate/photoresist interface can produce variations in the intensity of the radiation in the photoresist and thus, its exposure. Therefore, the reflection can affect the line width upon development. The reflected radiation can also expose portions of the photoresist coating that were not intended to be irradiated, thus impacting the pattern fidelity. One approach used to reduce these reflections is providing antireflective coating compositions (or “ARCs”) that can reduce the reflection of the radiation used to pattern an overlying photosensitive (also known as photoresist layer). The coating material can absorb the radiation.